Optical fingerprint authentication device

ABSTRACT

An optical fingerprint authentication device includes at least a light source and an image sensor and detects diffused light. The light source is an organic electroluminescence panel. The organic electroluminescence panel comprises a light emitting portion region and a light-transmitting non-light emitting portion, the light emitting portion region being shaped by an organic electroluminescence element. A fingerprint information reader having the image sensor arranged at a position adjacent to the non-light emitting portion is provided.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/060,532 filed Jun. 8, 2018, which in term was a 371 ofPCT/JP2016/075651 filed on Sep. 1, 2016, which, in turn, claimed thepriority of Japanese Patent Application No. JP 2015-239048 filed on Dec.8, 2015, all of the above applications are incorporated herein byreference.

TECHNOLOGICAL FIELD

The present invention relates to an optical fingerprint authenticationdevice which performs personal authentication with fingerprint byoptical method. More specifically, the present invention relates to anoptical fingerprint authentication device provided with a fingerprintinformation reader including an organic electroluminescent element whichis used as a light source for illumination.

DESCRIPTION OF THE RELATED ART

In recent years, the need of personal authentication with a biologicalpattern such as a fingerprint, vein, voiceprint, or iris of a user isincreasing as one of the method for specifying the user by an ATM(Automated Teller Machine) in a bank, a cellular phone, a PDA (PersonalData Assistant), a personal computer, and the like. Among these, thefingerprint is used in the oldest and proven biometric authenticationmethod. A fingerprint input device using a total reflection prism ispractically used for a long time, however, such device is not easilyminiaturized or suitable for mobile devices such as a laptop, PDA, and acellular phone. Therefore, thinned and miniaturized fingerprint inputdevices are variously disclosed.

For example, Japanese patent No. 3684233 discloses a light emittingdiode (hereinafter abbreviated as LED) arranged as a light source forillumination adjacent to a solid imaging element on a wiring substratefor an fingerprint pattern authentication method by causing a lightemitted from the LED for illumination to enter into a finger and bycausing the scattered light to be transmitted through a fingerprint andto enter into the solid imaging element.

Japanese Patent Application Laid Open Publication No. 2005-18595discloses an LED for illumination arranged adjacent to a solid imagingelement for a fingerprint pattern authentication method by causing thelight emitted from the LED for illumination to enter into a fingerthrough a protective member and causing the scattered light to betransmitted through a fingerprint and the protective member and to enterinto the solid imaging element.

Japanese Patent Application Laid Open Publication No. 2003-233805 andJapanese Patent Application Laid Open Publication No. 2005-38406disclose a circuit substrate having an image sensor (solid imagingelement) and a protective member laminated thereon. The disclosed methodincludes adhesion of a finger to the surface of the protective member,arranging an LED for illumination on the circuit substrate and adjacentto a light sensor, and irradiating the finger with the light through alight guide.

Patent document 1 discloses a fingerprint input device which includes anLED used as a light source for illumination and, while moving a fingerand an imaging element relative to each other, imaging a fingerprintpattern generated by the scattered light in the finger by the imagingelement.

Patent document 2 discloses an optical fingerprint input device whichirradiates a finger surface with the light from an LED and receives thereflected light from the finger surface by an imaging element. Animaging chip having a specific structure is provided in the proposedstructure.

However, since each fingerprint authentication device proposed as aboveincludes an LED used as a light source for illumination, an illuminationunit requires to incorporate a light guide plate and the like. Thisresults in a thick structure and thus causes a significant trouble fromthe viewpoint of providing a thin device. Furthermore, due to thestructure of an LED, there is a problem of difficulty in processing theLED into a shape having a curved surface, such as a round shape or anelliptic shape.

PRIOR ART DOCUMENT Patent Document

[Patent Document 1] Japanese Patent Application Laid Open PublicationNo. 2007-328511

[Patent Document 2] Japanese Patent Application Laid Open PublicationNo. 2005-118289

SUMMARY Problems to be Solved by the Invention

The present invention is conceived in view of the above problems, andthe object to be solved is to provide an optical fingerprintauthentication device which includes an organic electroluminescencepanel applied as a light source for illumination, has a thin structure,and is provided with a fingerprint information reader having variousshapes of light source for illumination according to purposes.

Means for Solving the Problem

As a result of intensive studies by the inventors in view of theproblems described above, it was found that an optical fingerprintauthentication device having a thin structure and various shapes of alight source for illumination according to purposes can be obtained byproviding an optical fingerprint authentication device which has atleast a light source and an image sensor and detects diffused light,wherein an organic electroluminescence panel (hereinafter also referredto as an organic EL panel) is used as the light source, the organic ELpanel includes a light emitting portion region which is shaped by anorganic electroluminescence element (hereinafter also referred to as anorganic EL element) and a light-transmitting non-light emitting portion,and a fingerprint information reader having the image sensor arranged ata position adjacent to at least the non-light emitting portion.

That is, the above-described problems of the present invention aresolved by the following means.

To achieve at least one of the abovementioned objects, according to anaspect of the present invention, an optical fingerprint authenticationdevice which includes at least a light source and an image sensor anddetects diffused light,

wherein the light source is an organic electroluminescence panel,

wherein the organic electroluminescence panel includes a light emittingportion region and a light-transmitting non-light emitting portion, thelight emitting portion region being shaped by an organicelectroluminescence element; and

wherein a fingerprint information reader having the image sensorarranged at a position adjacent to the non-light emitting portion isprovided.

Advantageous Effects of Invention

According to the present invention, it is possible to provide an opticalfingerprint authentication device having a thin structure and providedwith a fingerprint information reader having various shapes of lightsource for illumination according to purposes.

The technical features of the optical fingerprint authentication devicedefined in the present invention and the way how it exhibitsadvantageous effects are estimated as follows.

An LED, which is advantageous regarding life as a light source, iswidely used as a light source for illumination in a conventional opticalfingerprint authentication device as described above, however, raisesproblems such as a thick structure and difficulty in processing intovarious shapes, due to the principle of light emission.

As a method for solving such problems, the present inventors have foundthat the above-described problems can be solved by applying an organicelectroluminescence panel provided with an organic EL element as a lightsource

That is, while utilizing the features of an organic EL element, which isa thin-film light emitting element, the formation method thereof (forexample, a chemical vapor deposition method or a wet application method)allows to form an organic EL element having an arbitrary light emissionpattern, so that it is possible to design fingerprint informationreaders having a detection area of various shapes required for theoptical fingerprint authentication device, and to correspond tofingerprint authentication devices for various needs. Furthermore, it ispossible to improve the recognition rate by the fingerprintauthentication device by achieving a light source for illumination withuniform light having various shapes.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features provided by one or more embodiments of theinvention will become more fully understood from the detaileddescription given hereinbelow and the appended drawings which are givenby way of illustration only, and thus are not intended as a definitionof the limits of the present invention.

FIG. 1 is a schematic view showing an example of an entire structure ofa fingerprint information reader constituting an optical fingerprintauthentication device of the present invention.

FIG. 2 is a schematic cross-sectional view showing an exemplarystructure of an organic EL element which can be applied to the presentinvention.

FIG. 3 is a schematic cross-sectional view showing an exemplarystructure of an organic EL panel which can be applied to the presentinvention (Embodiment 1).

FIG. 4 is a schematic cross-sectional view showing another exemplarystructure of an organic EL panel which can be applied to the presentinvention (Embodiment 2).

FIG. 5 is a schematic cross-sectional view showing another exemplarystructure of an organic EL panel which can be applied to the presentinvention (Embodiment 3).

FIG. 6 is a schematic cross-sectional view showing another exemplarystructure of an organic EL panel which can be applied to the presentinvention (Embodiment 4).

FIG. 7 is a schematic cross-sectional view showing another exemplarystructure of an organic EL panel which can be applied to the presentinvention (Embodiment 5).

FIG. 8A is a schematic cross-sectional view showing the first step of aformation method of an organic EL panel which can be applied to thepresent invention (Embodiment 6).

FIG. 8B is a schematic cross-sectional view showing the second step of aformation method of an organic EL panel which can be applied to thepresent invention (Embodiment 6).

FIG. 8C is a schematic cross-sectional view showing the third step of aformation method of an organic EL panel which can be applied to thepresent invention (Embodiment 6).

FIG. 9 is a schematic diagram showing an exemplary optical fingerprintauthentication device provided with a fingerprint information readerhaving an organic EL panel provided with a doughnut-shaped organic ELelement (Embodiment 7).

FIG. 10 is a schematic diagram showing an exemplary optical fingerprintauthentication device provided with a fingerprint information readerhaving an organic EL panel provided with a rectangular-shaped organic ELelement (Embodiment 8).

FIG. 11 is a schematic diagram showing an exemplary optical fingerprintauthentication device provided with a fingerprint information readerhaving an organic EL panel provided with strip-shaped organic ELelements arranged at four sides (Embodiment 9).

FIG. 12 is a schematic diagram showing an exemplary optical fingerprintauthentication device provided with a fingerprint information readerhaving a round-shaped organic EL panel provided with arectangular-shaped non-light emitting portion at the center (Embodiment10).

FIG. 13 is a schematic diagram showing an exemplary optical fingerprintauthentication device provided with a fingerprint information readerhaving an organic EL panel provided with a plurality of strip-shapedorganic EL elements arranged in a stripe shape in parallel (Embodiment11).

FIG. 14 is a schematic diagram showing an example of an opticalfingerprint authentication device provided with an optical fingerprintinformation reader having an organic EL panel with a plurality oforganic EL elements arranged separately at a peripheral portion(Embodiment 12).

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, one or more embodiments of the present invention will bedescribed with reference to the drawings. However, the scope of theinvention is not limited to the disclosed embodiments.

According to the present invention, it is possible to provide an opticalfingerprint authentication device having a thin structure and providedwith a fingerprint information reader having various shapes of lightsource for illumination according to purposes.

The technical features of the optical fingerprint authentication devicedefined in the present invention and the way how it exhibitsadvantageous effects are estimated as follows.

An LED, which is advantageous regarding life as a light source, iswidely used as a light source for illumination in a conventional opticalfingerprint authentication device as described above, however, raisesproblems such as a thick structure and difficulty in processing intovarious shapes, due to the principle of light emission.

As a method for solving such problems, the present inventors have foundthat the above-described problems can be solved by applying an organicelectroluminescence panel provided with an organic EL element as a lightsource.

That is, while utilizing the features of an organic EL element, which isa thin-film light emitting element, the formation method thereof (forexample, a chemical vapor deposition method or a wet application method)allows to form an organic EL element having an arbitrary light emissionpattern, so that it is possible to design fingerprint informationreaders having a detection area of various shapes required for theoptical fingerprint authentication device, and to correspond tofingerprint authentication devices for various needs. Furthermore, it ispossible to improve the recognition rate by the fingerprintauthentication device by achieving a light source for illumination withuniform light having various shapes.

The optical fingerprint authentication device of the present inventionhas at least a light source and an image sensor and provided with afingerprint information reader to detect diffused light. As the lightsource is included an organic electroluminescence panel which includes alight emitting portion region shaped by an organic electroluminescenceelement and a light-transmitting non-light emitting portion. The imagesensor is arranged at a position adjacent to the non-light emittingportion. These features are technical features commonly owned by theinvention recited in each claim.

As an embodiment of the present invention, from the viewpoint ofexhibiting objective effects of the present invention further, theorganic EL element preferably includes an organic functional layer unitbetween a pair of electrodes facing each other. One of the electrodes isa light-transmitting electrode and the other is a non-light transmittingelectrode, so that only one of the surface sides is the light emittingsurface. Such structure is preferred in that the fingerprint detector isefficiently irradiated with irradiation light and that the image sensorcan receive light with enhanced sensitivity.

Alternatively, according to the structure of the organic EL panel, theorganic EL element may include the pair of electrodes facing each otherwhich are both light-transmitting electrodes, so that the organic ELelement is designed to be a both-face light emission type.

Preferably, transparent electrode(s) included in the organic EL elementincludes an oxide semiconductor or a thin film of a metal or an alloy,in that electrode(s) having both high light transmittance and excellentconductivity can be obtained.

Preferably, at the light-transmitting non-light emitting portion isformed a light-transmitting electrode or are provided alight-transmitting electrode and an organic functional layer unit, sothat the method of manufacturing an optical fingerprint authenticationdevice becomes easier.

According to preferred arrangement patterns of the organic EL element ofthe organic EL panel included in the optical fingerprint input device ofthe present invention, the organic EL element may be arranged at theperipheral portion of a elliptic shape to form a light-transmittingnon-light emitting portion at the center portion, or a plurality ofstrip-shaped organic EL elements may be arranged separately in parallelto form a light-transmitting non-light emitting portion between theorganic EL elements, in that optical information required forfingerprint authentication can be efficiently acquired.

Preferably, the organic electroluminescence panel is designed to emitlight which has a wavelength in a visible light region or light whichhas a wavelength in an infrared region, in that the usage can beexpanded.

The “organic EL panel” according to the present invention indicates astructure including the light emitting portion region shaped by theorganic EL element and the light-transmitting non-light emitting portionon the same plane.

The “organic EL element” according to the present invention indicates asurface light source which irradiate a specimen surface (specifically, afingerprint surface) with light for fingerprint authentication. Mainlyon a transparent base material are provided a pair of light-transmittingelectrodes facing each other (an anode and a cathode) or a pair ofelectrodes which are constituted by a light-transmitting electrode and anon-light-transmitting electrode, an organic functional layer unitbetween the pair of electrodes constituted by a carrier transportingfunctional layer which mainly controls the transportation of electronsor holes and a light emitting layer, and a sealing member furtherprovided thereon. However, for convenience of explanation, thedescription or explanation of the sealing member is omitted in somecases. Furthermore, in the detailed description of embodiments of thepresent invention described below, control circuits and wires to controllight emission from the organic EL element are omitted.

The “organic functional layer unit” according to the present inventionis explained with reference to FIG. 2 detailed below, and exemplified bya structure including a first carrier transporting functional layergroup 1 (for example, a hole injecting layer, a hole transporting layer,and the like), a light emitting layer including a phosphorescentmaterial and the like, and a second carrier transporting functionallayer group 2 (for example, a hole blocking layer, electron transportinglayer, electron injecting layer, and the like) which are arranged inlayers on a base material.

The “light emitting area” according to the present invention indicates aregion in which all of the anode, the organic functional layer unit, andthe cathode exist when viewed in the thickness direction.

The “anode” according to the present invention is also referred to asthe “first electrode” and indicates an electrode to apply (+) as avoltage. The “cathode” according to the present invention is alsoreferred to as the “second electrode” and indicates an electrode toapply (−) as a voltage.

The “light transmittance” according to the present invention indicatesthat the light transmission rate at the wavelength of 550 nm is 60% ormore, preferably 70% or more, more preferably 80% or more. The “no lighttransmittance” indicates that the light transmission rate at thewavelength of 550 nm is 40% or less, preferably 30% or less, morepreferably 20% or less.

Hereinafter, components of the present invention and embodiments tocarry out the present invention will be described in detail withreference to the drawings. Throughout the specification, “to”representing a range of numerical values is used to indicate that thevalues described before and after “to” are respectively included as thelower limit and the upper limit. Numeral codes in each drawing arerepresented by numbers in parentheses at the end of the components inthe explanation of each drawing.

<<Basic Structure of Optical Fingerprint Authentication Device>>

The optical fingerprint authentication device according to the presentinvention mainly includes a light source and an image sensor. The lightsource is an organic EL panel constituted by a light emitting portionregion and a light-transmitting non-light emitting portion. The lightemitting portion region is constituted by an organic EL element. Theoptical fingerprint authentication device is provided with a fingerprintinformation reader with the image sensor arranged at a position adjacentto the non-light emitting portion.

FIG. 1 is a schematic diagram showing an example of entire structure ofa fingerprint information reader included in an optical fingerprintauthentication device of the invention.

As the fingerprint information reader (100) of the optical fingerprintauthentication device shown in FIG. 1, there are provided an organic ELpanel (P) which is constituted by organic EL elements (OLEDs) and alight-transmitting non-light emitting portion (12), and an image sensor(S) which is arranged below the light-transmitting non-light emittingportion (12) and optically reads fingerprint information of a specimen.11 is a glass substrate to hold a finger (F).

The organic EL elements (OLEDs) as light sources constituting theorganic EL panel (P) emit light (L1, also referred to as irradiationlight) and irradiate the fingerprint surface of the finger (F) with thelight (L1). The reflection light (L2, also referred to as a lightsignal) from the finger surface is transmitted through thelight-transmitting non-light emitting portion (12) of the organic ELpanel (P). Optical information is read by the image sensor (S) and,though not shown in the drawings, image information read by the imagesensor (S) is analyzed and compared with the stored (registered)fingerprint information by the image sensor (S) to perform fingerprintauthentication.

The image sensor (S) applied to the optical fingerprint authenticationdevice according to the present invention is also referred to as a solidimaging element and may be, for example, an image sensor of a CCD(Charge Coupled Device) type or a CMOS (Complementary Metal OxideSemiconductor) type

<<Basic Structure of Organic EL Element>>

Next, with reference to the drawings will now be described basicstructures of the organic EL element constituting the organic EL panelaccording to the present invention.

FIG. 2 is a schematic cross-sectional view showing a basic structure ofan organic EL element including the organic functional layer unit whichcan be applied to the present invention.

The organic EL element (OLED) according to the present invention shownin FIG. 2 has a structure in which an organic functional layer unit (U)including a light emitting layer is laminated on a transparent substrate(1) having light transmittance, such as a glass substrate or a flexibleresin substrate,

According to the example shown in FIG. 2, a gas barrier layer (2) isformed on the transparent substrate (1) having light transmittance. Anorganic functional layer unit (U) is constituted by the anode (3) formedas a first electrode on the gas barrier layer (2), on which sequentiallylaminated are the first carrier transporting functional layer group 1(4) constituted by, for example, the hole injecting layer, the holetransporting layer, and the like, the light emitting layer (5), and thesecond carrier transporting functional layer group 2 (6) constituted by,for example, the electron transporting layer, the electron injectinglayer, and the like. Furthermore, above the organic functional layerunit (U) is provided a cathode (7) as the second electrode. The organicEL element (OLED) is formed by providing a sealing substrate (10) havinga sealing adhesion layer (8) and a gas barrier layer (9) and coveringthe above-described entire laminate.

According to the structure shown in FIG. 2, the anode (3) as the firstelectrode is the transparent electrode having light transmission ratedefined above, and the cathode (7) as the second electrode is anelectrode having no light transmittance. In an exemplary method, lightirradiation (L1) of the finger (F) is performed from a finger surfaceside, on which the anode (3) is arranged.

As shown in FIG. 2, a light emitting area is defined as a region inwhich all of the anode (3), the organic functional layer unit (U), thelight emitting layer (5) in particular, and the cathode (7) are presentin a single plane.

[Component of Organic EL Element]

First of all, the details of main components of the organic EL elementconstituting the organic EL panel according to the present invention areexplained.

In the organic EL element (OLED) according to the present invention, asexplained with reference to FIG. 2, a light emitting region isconstituted by laminating, on the transparent substrate (1) having thegas barrier layer (2), the light-transmitting anode (3) as the firstelectrode, the carrier transporting functional layer group 1 (4)constituted by, for example, the hole injecting layer and the holetransporting layer, the light emitting layer (5), and the carriertransporting functional layer group 2 (6) constituted by, for example,the electron transporting layer and the electron injecting layer. Thecathode (7) and the sealing substrate (10) having the sealing adhesivelayer (8) and the gas barrier layer (9) are further provided thereon.

Typical structure of the organic EL element is shown below:

(i) Anode having light transmittance (3)/Organic functional layer unit(U) [Carrier transporting functional layer group 1 (4: Hole injectingtransporting layer)/Light emitting layer (5)/Carrier transportingfunctional layer group 2 (6: Electron injecting transportinglayer)]/Cathode having no light transmittance (7)(ii) Anode having light transmittance (3)/Organic functional layer unit(U) [Carrier transporting functional layer group 1 (4: Hole injectingtransporting layer)/Light emitting layer (5)/Carrier transportingfunctional layer group 2 (6: Hole blocking layer/Electron injectingtransporting layer)]/Cathode having no light transmittance (7)(iii) Anode having light transmittance (3)/Organic functional layer unit(U) [Carrier transporting functional layer group 1 (4: Hole injectingtransporting layer/Electron blocking layer)/Light emitting layer(5)/Carrier transporting functional layer group 2 (6: Hole blockinglayer/Electron injecting transporting layer)]/Cathode having no lighttransmittance (7)(iv) Anode having light transmittance (3)/Organic functional layer unit(U) [Carrier transporting functional layer group 1 (4: Hole injectinglayer/Hole transporting layer)/Light emitting layer (5)/Carriertransporting functional layer group 2 (6: Electron transportinglayer/Electron injecting layer)]/Cathode having no light transmittance(7)(v) Anode having light transmittance (3)/Organic functional layer unit(U) [Carrier transporting functional layer group 1 (4: Hole injectinglayer/Hole transporting layer)/Light emitting layer (5)/Carriertransporting functional layer group 2 (6: Hole blocking layer/Electrontransporting layer/Electron injecting layer)]/Cathode having no lighttransmittance (7)(vi) Anode having light transmittance (3)/Organic functional layer unit(U) [Carrier transporting functional layer group 1 (4: Hole injectinglayer/Hole transporting layer/Electron blocking layer)/Light emittinglayer (5)/Carrier transporting functional layer group 2 (6: Holeblocking layer/Electron transporting layer/Electron injectinglayer)]/Cathode having no light transmittance (7)

In the structures explained in (i) to (vi) above, the cathode (7) isexplained to have no light transmittance, however, if necessary, thecathode may have light transmittance as well as the anode.

Further, a non-light emitting intermediate layer may be provided betweenthe light-emitting layers. The intermediate layer may be an electrongenerating layer or may have a multiphoton emission structure.

The detailed structures of the organic EL elements applicable to thepresent invention are disclosed in, for example, Japanese UnexaminedPatent Application Publication Nos. 2013-157634, 2013-168552,2013-177361, 2013-187211, 2013-191644, 2013-191804, 2013-225678,2013-235994, 2013-243234, 2013-243236, 2013-242366, 2013-243371,2013-245179, 2014-003249, 2014-003299, 2014-013910, 2014-017493, and2014-017494.

A tandem type organic EL element can also be used. Examples of a tandemtype organic EL element are described in: U.S. Pat. Nos. 6,337,492,7,420,203, 7,473,923, 6,872,472, 6,107,734, and 6,337,492, InternationalPublication No. 2005/009087, Japanese Unexamined Patent ApplicationPublication Nos. 2006-228712, 2006-24791, 2006-49393, 2006-49394,2006-49396, 2011-96679, and 2005-340187, JP Patent Nos. 4711424,3496681, 3884564, and 4213169, Japanese Unexamined Patent ApplicationPublication Nos. 2010-192719, 2009-076929, 2008-078414, 2007-059848,2003-272860, and 2003-045676, and International Publication No.2005/094130. The structures of the elements and the composing materialsare described in these documents, however, the present invention is notlimited to them.

Individual layers constituting the organic EL element will now bedescribed.

[Transparent Substrate]

The transparent substrate (1) applied to the organic EL element (OLED)is not particularly limited and may be any substrate having lighttransmittance, such as glass, plastics, and the like.

Examples of the substrate (1) having light transmittance which can beapplied to the present invention include glass, quartz, and resinsubstrate. A flexible resin material is more preferred in thatflexibility can be provided to the organic EL element.

Examples of the resin material constituting the resin substrate whichcan be applied to the present invention include polyesters such aspoly(ethylene terephthalate) (abbreviation: PET) and poly(ethylenenaphthalate) (abbreviation: PEN); polyethylene; polypropylene;cellophane; cellulose esters and derivatives thereof, such as cellulosediacetate, cellulose triacetate (abbreviation: TAC), cellulose acetatebutyrate, cellulose acetate propionate (abbreviation: CAP), celluloseacetate phthalate, and cellulose nitrate; poly(vinylidene chloride);poly(vinyl alcohol); poly(ethylene-vinyl alcohol); syndiotacticpolystyrene; polycarbonates (abbreviation: PC); norbornene resins;polymethylpentene; polyether ketones; polyimides, polyether sulfones(abbreviation: PES); poly(phenylene sulfide); polysulfones; polyetherimides; polyether ketone imides; polyamides; fluorinated resins; nylons;poly(methyl methacrylate); acrylics and polyallylates; and cycloolefinresins, such as Arton (commercial name, available from JSR) and Apel(commercial name, available from Mitsui Chemicals, Inc.).

Among these resin materials, films of polyethylene terephthalate(abbreviation: PET), polybutylene terephthalate, polyethylenenaphthalate (abbreviation: PEN), and polycarbonate (abbreviation: PC)are preferably used as resin substrates having flexibility with respectto the cost or the easy availability.

The resin substrate described above may be an un-stretched film or astretched film.

The resin substrate which can be applied to the present invention can bemanufactured by a conventionally known common method for manufacturingfilms. For example, a resin as a material is melted by an extruder,extruded through a ring die or a T-die, and rapidly cooled, so that anunstretched resin substrate, which is substantially amorphous and is notoriented, can be produced. A stretched resin substrate can be producedby stretching the unstretched resin substrate in the moving direction ofthe resin substrate (longitudinal direction, MD direction) or thedirection perpendicular to the moving direction of the resin substrate(lateral direction, TD direction) by a well-known method such as oneaxis stretching, tenter type sequential biaxial stretching, tenter typesimultaneous biaxial stretching, or tubular simultaneous biaxialstretching. The stretching ratio in this case can be appropriatelyselected according to the resin which is the raw material of the resinsubstrate, and is preferably within 2 to 10 times in each oflongitudinal direction and lateral direction.

The resin substrate is preferably a thin film having a thickness withinthe range of 3 to 200 μm, more preferably within the range of 10 to 150μm, particularly preferably within the range of 20 to 120 μm.

Examples of the glass substrate which can be applied as the substratehaving light transmittance according to the present invention includesoda lime glass, barium and strontium containing glass, lead glass,aluminosilicate glass, borosilicate glass, barium borosilicate glass,and quartz.

[First Electrode: Anode]

The anode constituting the organic EL element is preferably an electrodehaving light transmittance and preferably includes, for example, anoxide semiconductor or a thin film of a metal or an alloy. For example,metals such as Ag and Au, alloys primarily composed of such metals, CuI,indium-tin complex oxide (ITO), and oxide semiconductors such as SnO₂and ZnO.

The formation method of the anode may be, for example, a vacuumevaporation method (such as a resistance heating deposition method, anelectron beam deposition method, an ion plating method, and an ion beamevaporation method), a sputtering method, a reactive sputtering method,a molecular beam epitaxy method, a plasma polymerization method, anatmospheric-pressure plasma polymerization method, a plasma CVD method,a laser CVD method, a thermal CVD method, and the like.

In the case where an anode having light transmittance is primarilycomposed of silver, the purity of silver is preferably 99% or more.Palladium (Pd), copper (Cu) or gold (Au) may be added in order to keepthe stability of silver.

The anode having light transmittance is a layer mainly composed ofsilver. Specifically, it may be composed of silver alone or of an alloyincluding silver (Ag). Examples of such alloy include silver-magnesium(Ag—Mg), silver-copper (Ag—Cu), silver-palladium (Ag—Pd),silver-palladium-copper (Ag—Pd—Cu), and silver-indium (Ag—In).

Among the composing materials of the above-described anode, the anodeconstituting the organic EL element according to the present inventionpreferably includes silver as a main component, has a thickness withinthe range of 2 to 20 nm, more preferably within the range of 4 to 12 nm,and has light transmittance. A thickness of 20 nm or less is preferredbecause absorption and reflection of light by the anode having lighttransmittance can be reduced and thus high light transmittance can bemaintained.

The layer primarily composed of silver according to the presentinvention indicates that the anode having light transmittance containssilver in the amount of 60 mass % or more, preferably 80 mass % or more,more preferably 90 mass % or more, most preferably 98 mass % or more.The “light transmittance” used for the anode having light transmittanceaccording to the present invention indicates that the light transmissionrate is 50% or more at the wavelength of 550 nm.

The anode having light transmittance may be a plurality of separate andlaminated layers as needed, primarily composed of silver.

In the present invention, in the case where the anode is primarilycomposed of silver and has light transmittance, from the viewpoint ofimproving uniformity of the silver layer composing the anode havinglight transmittance, a ground layer is preferably arranged under theanode. The ground layer is not particularly limited as long asaggregation of silver can be suppressed while producing a film anodecomposed of silver or an alloy including silver as a main component. Thelayer preferably includes an organic compound having a nitrogen atom ora sulfur atom, for example. Preferably, the anode having lighttransmittance is formed on the ground layer.

[Organic Functional Layer Unit] (Light Emitting Layer)

A phosphorescent compound or a fluorescent compound can be used as alight emitting material in the light emitting layer (5) constituting theorganic EL element (OLED). In the present invention, the light emittingmaterial preferably includes a phosphorescent compound, in particular.

Electrons injected from an electrode or the electron transporting layerand holes injected from the hole transporting layer recombine in thelight emitting layer to emit light. Light may be emitted in the lightemitting layer or at an interface between the light emitting layer andthe adjacent layer.

The light emitting layer may have any structures, as long as theincluded light emitting material satisfies requirements for lightemission. The light emitting layer may be composed of a plurality oflayers having the same emission spectrum or the same maximum emissionwavelength. In this case, a non-light emitting intermediate layer ispreferably arranged between the individual light emitting layers.

The total thickness of the light emitting layer is preferably within therange of 1 to 100 nm, more preferably 1 to 30 nm to reduce the drivingvoltage. When a non-light emitting intermediate layer is present betweenthe light emitting layers, the total thickness of the light emittinglayer includes the thickness of the intermediate layer.

The light emitting layer described above may be formed with lightemitting material(s) and host compound(s), which will be describedbelow, by any known method, such as vacuum evaporation, spin coating,casting, LB (Langmuir-Blodgett) coating, or ink jetting.

The light emitting layer may be composed of a plurality of lightemitting materials, for example, a phosphorescent material and afluorescent material (also referred to as a fluorescent dopant orfluorescent compound) may be mixed to be used in a single light emittinglayer. In a preferred embodiment, the light emitting layer includes ahost compound (also referred to as a light emitting host and the like)and a light emitting material (also referred to as a light emittingdopant compound) so that the light emitting material emits light.

<Host Compound>

Preferred host compounds to be included in the light emitting layer havea phosphorescence quantum yield of less than 0.1 at room temperature(25° C.). More preferably, the phosphorescence quantum yield is lessthan 0.01. In the compound included in the luminous layer, the volumefraction of the host compound is preferably 50% or more.

Any known host compound may be used alone or in combination. A pluralityof kinds of host compounds may be used to adjust charge transfer andthus to enhance the efficiency of the organic electroluminescentelement. A plurality of light emitting materials described below may beused to mix light having different colors and thus to emit light with adesired color.

The host compounds used in the light emitting layer may be any known lowmolecular weight compound, any high molecular weight compound havingrepeating units, or any low molecular weight compound having apolymerizable group such as a vinyl group or an epoxy group(evaporation-polymerizable light emitting host).

The host compounds which can be applied to the present invention includecompounds disclosed in, for example, Japanese Unexamined PatentApplication Publication Nos. 2001-257076, 2001-357977, 2002-8860,2002-43056, 2002-105445, 2002-352957, 2002-231453, 2002-234888,2002-260861, and 2002-305083; United States Patent Application Nos.2005/0112407 and 2009/0030202; WO 2001/039234, WO 2008/056746, WO2005/089025, WO 2007/063754, WO 2005/030900, WO 2009/086028, and WO2012/023947; Japanese Unexamined Patent Application Publication No.2007-254297; and EP 2034538.

<Light Emitting Material>

Examples of the light emitting material which can be used in the presentinvention include phosphorescent compounds (also referred to asphosphorescent materials or phosphorescent dopants) and fluorescentcompounds (also referred to as fluorescent materials). In particular,phosphorescent compounds are preferably used due to their high lightemitting efficiency.

<Phosphorescent Compound>

Phosphorescent compounds are defined as compounds which emit light fromthe excited triplet state and, specifically, which emit phosphorescentlight at room temperature (25° C.) and have a phosphorescent quantumyield of 0.01 or more at 25° C. The phosphorescent quantum yield ispreferably 0.1 or more.

The phosphorescent quantum yield described above may be determined bythe method described in the Fourth Series of Experimental Chemistry,Vol. 7 Spectroscopy II, page 398 (1992, published by Maruzen). Thephosphorescent quantum yield in a solution may be determined with anysolvent, and phosphorescent compounds having a phosphorescent quantumyield of 0.01 or more determined with any solvent may be used in thepresent invention.

The phosphorescent compound may be appropriately selected from any knownphosphorescent compounds used in light emitting layers of common organicEL elements. Preferred are complexes containing metal atoms belonging togroups 8 to 10 in the periodic table, more preferred are iridiumcompounds, osmium compounds, platinum compounds (platinum-basedcomplexes), or rare earth complexes, and most preferred are iridiumcompounds.

In the present invention, at least one light emitting layer may containtwo or more phosphorescent compounds. The concentration of thesephosphorescent compounds in the light emitting layer may vary along thethickness direction of the light emitting layer.

Examples of the phosphorescent compounds which can be used in thepresent invention are listed in the following documents.

Nature 395,151 (1998), Appl. Phys. Lett. 78, 1622(2001), Adv. Mater. 19,739(2007), Chem. Mater. 17, 3532(2005), Adv. Mater. 17, 1059(2005),International Publication Nos. 2009/100991, 2008/101842, and2003/040257, and United States Patent Application Nos. 2006/835469,2006/0202194, 2007/0087321, and 2005/0244673.

Further examples include Inorg. Chem. 40, 1704(2001), Chem. Mater. 16,2480(2004), Adv. Mater. 16, 2003(2004), Angew. Chem. Int. Ed. 2006, 45,7800, Appl. Phys. Lett. 86, 153505(2005), Chem. Lett. 34, 592(2005),Chem. Commun. 2906 (2005), Inorg. Chem. 42, 1248(2003), InternationalPublication Nos. 2009/050290 and 2009/000673, U.S. Pat. No. 7,332,232,United States Patent Application No. 2009/0039776, U.S. Pat. No.6,687,266, United States Patent Application Nos. 2006/0008670 and2008/0015355, U.S. Pat. No. 7,396,598, United States Patent ApplicationNo. 2003/0138657, and U.S. Pat. No. 7,090,928.

Further examples include Angew. Chem. Int. Ed. 47, 1 (2008), Chem.Mater. 18, 5119(2006), Inorg. Chem. 46, 4308(2007), Organometallics 23,3745(2004), Appl. Phys. Lett. 74, 1361(1999), International PublicationNos. 2006/056418, 2005/123873, 2005/123873, and 2006/082742, UnitedStates Patent Application No. 2005/0260441, U.S. Pat. No. 7,534,505,United States Patent Application No. 2007/0190359, U.S. Pat. Nos.7,338,722 and 7,279,704, and United States Patent Application No.2006/103874.

Further examples include International Publication Nos. 2005/076380,2008/140115, 011/134013, 2010/086089, 2012/020327, 2011/051404, and2011/073149, and Japanese Unexamined Patent Application Publication Nos.2009-114086, 2003-81988, and 2002-363552.

Preferred phosphorescent compounds in the present invention includeorganometallic complexes containing iridium (Ir) as a central atom. Morepreferred are complexes having at least one of the coordinate bondselected from a metal-carbon bond, a metal-nitrogen bond, a metal-oxygenbond, and a metal-sulfur bond.

Such phosphorescent compounds (also referred to as phosphorescent metalcomplexes) may be prepared by the processes described, for example, inthe following documents and references cited in these documents: OrganicLetter, vol. 3, No. 16, pp. 2579-2581 (2001), Inorganic Chemistry, vol.30, No. 8, pp. 1685-1687 (1991), J. Am. Chem. Soc., vol. 123, p. 4304(2001), Inorganic Chemistry, vol. 40, No. 7, pp. 1704-1711 (2001),Inorganic Chemistry, vol. 41, No. 12, pp. 3055-3066 (2002), New Journalof Chemistry., vol. 26, P. 1171 (2002), and European Journal of OrganicChemistry, vol. 4, pp. 695-709 (2004).

<Fluorescent Compound>

The fluorescent compound include coumarin dyes, pyran dyes, cyaninedyes, croconium dyes, squarylium dyes, oxobenzanthracene dyes,fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbenedyes, polythiophene dyes, and rare earth complex phosphors.

(Carrier Transporting Functional Layer Group)

Next, typical example of individual layers constituting the carriertransporting functional layer group, the charge injecting layer, thehole transporting layer, the electron transporting layer, and a blockinglayer, will now be described in sequence.

(Charge Injecting Layer)

The charge injecting layer is a layer provided between the electrode andthe light emitting layer, so that the driving voltage is reduced and theemission luminance is improved. The detail of the charge injecting layeris described in “Yuuki EL Soshi to sono Kogyoka Saizensen (Front Line inIndustrialization of Organic EL element)”, Part II, Chapter 2, pp.123-166, “Denkyoku Zairyo (Electrode materials)” (Nov. 30, 1998 by N. T.S. Company). The charge injecting layer is classified into a holeinjecting layer and an electron injecting layer.

Among the charge injecting layer, the hole injecting layer is usuallyarranged between the anode and the light emitting layer or the holetransporting layer, while the electron injecting layer is usuallyarranged between the cathode and the light emitting layer or theelectron transporting layer. The present invention is characterized inthat the charge injecting layer is arranged adjacent to an electrodehaving light transmittance. In the case where the charge injecting layeris used as an intermediate electrode, at least one of the adjacentelectron injecting layer and the hole injecting layer is required tosatisfy the requirement of the present invention.

The hole injecting layer is a layer provided adjacent to the anode whichis a light-transmitting electrode, so that the driving voltage isreduced and the emission luminance is improved. The detail of the chargeinjecting layer is described in “Yuuki EL Soshi to sono KogyokaSaizensen (Front Line in Industrialization of Organic EL element)”, PartII, Chapter 2, pp. 123-166, “Denkyoku Zairyo (Electrode materials)”(Nov. 30, 1998 by N. T. S. Company).

The hole injecting layer is also described in detail in JapaneseUnexamined Patent Application Publication Nos. Hei 9-45479, Hei9-260062, and Hei 8-288069. Examples of materials for the hole injectinglayer include porphyrin derivatives, phthalocyanine derivatives, oxazolederivatives, oxadiazole derivatives, triazole derivatives, imidazolederivatives, pyrazoline derivatives, pyrazolone derivatives,phenylenediamine derivatives, hydrazone derivatives, stilbenederivatives, polyarylalkane derivatives, triarylamine derivatives,carbazole derivatives, indrocarbazole derivatives, isoindolederivatives, acene derivatives such as anthracene and naphthalene,fluorene derivatives, fluorenone derivatives, polyvinylcarbazole, highmolecular weight materials or oligomers having aromatic amine main orside chains, polysilanes, and conductive polymers or oligomers (forexample, polyethylene dioxythiophene (PEDOT)/polystyrene sulfonate(PSS), aniline copolymers, polyaniline, and polythiophene).

Examples of the triarylamine derivatives include benzidine types such asα-NPD (4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl), star-burst typessuch as MTDATA(4,4′,4″-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine), andcompounds having fluorene and anthracene in the triarylamine couplingcores.

Alternatively, the hole transporting material may be hexaazatriphenylenederivatives described in Japanese translation of PCT application2003-519432 and Japanese Unexamined Patent Application Publication No.2006-135145.

The electron injecting layer is a layer provided between the cathode andthe light emitting layer, so that the driving voltage is reduced and theemission luminance is improved. In the case where the cathode includesan electrode having light transmittance according to the presentinvention, the electron injecting layer is provided adjacent to theelectrode having light transmittance. The detail of the electroninjecting layer is described in “Yuuki EL Soshi to sono KogyokaSaizensen (Front Line in Industrialization of Organic EL element)”, PartII, Chapter 2, pp. 123-166, “Denkyoku Zairyo (Electrode materials)”(Nov. 30, 1998 by N. T. S. Company).

The electron injecting layer is also described in detail, for example,in Japanese Unexamined Patent Application Publication Nos. Hei 6-325871,Hei 9-17574, and Hei 10-74586. Examples of preferred materials for theelectron injecting layer include metals such as strontium and aluminum;alkali metal compounds such as lithium fluoride, sodium fluoride, andpotassium fluoride; alkali metal halides such as magnesium fluoride andcalcium fluoride; alkaline earth metal compounds such as magnesiumfluoride; metal oxides such as molybdenum oxide and aluminum oxide; andmetal complexes such as lithium-8-hydroxyquinolate (Liq). In the casewhere the cathode is an electrode having light transmittance accordingto the present invention, organic materials such as metal complexes areparticularly preferred. Preferably, the electron injecting layer shouldhave a significantly small thickness within the range of 1 nm to 10 μm,although it depends on the materials constituting the layer.

(Hole Transporting Layer)

The hole transporting layer is composed of a hole transporting material,which has a function of transporting holes. The hole injecting layer andthe electron blocking layer also function as a hole transporting layerin a broad sense. The hole transporting layer may have a monolayer ormultilayer structure.

The hole transporting material inject holes, transport holes, or blockelectrons and may be either organic or inorganic compound. Examples ofsuch materials include triazole derivatives, oxadiazole derivatives,imidazole derivatives, polyarylalkane derivatives, pyrazolinederivatives, pyrazolone derivatives, phenylenediamine derivatives,arylamine derivatives, amino-substituted chalcone derivatives, oxazolederivatives, styrylanthracene derivatives, fluorenone derivatives,hydrazone derivatives, stilbene derivatives, silazane derivatives,aniline copolymers, conductive high molecular weight oligomers, andthiophene oligomers.

The hole transporting material may be porphyrin compounds, tertiaryaromatic amine compounds, and styrylamine compounds, besides thecompounds described above. Preferred are tertiary aromatic aminecompounds, in particular.

Typical examples of the tertiary aromatic amine compounds andstyrylamine compounds include N,N,N′,N′-tetraphenyl-4,4′-diaminophenyl,N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(abbreviation: TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane,1,1-bis(4-di-p-tolylaminophenyl)cyclohexane,N,N,N′,N′-tetra-p-tolyl-4,4′-diaminobiphenyl,1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane,bis(4-dimethylamino-2-methylphenyl)phenylmethane,bis(4-di-p-tolylaminopnenyl)phenylmethane,N,N′-diphenyl-N,N′-di(4-methoxyphenyl)-4,4′-diaminobiphenyl,N,N,N′,N′-tetraphenyl-4,4′-diaminodiphenyl ether,4,4′-bis(diphenylamino)quodriphenyl, N,N,N-tri(p-tolyl)amine,4-(di-p-tolylamino)-4′-[4-(di-p-tolylamino)styryl]stilbene,4-N,N-diphenylamino-(2-diphenylvinyl)benzene,3-methoxy-4′-N,N-diphenylaminostyrylbenzene, and N-phenylcarbazole.

A thin film of the hole transporting layer can be formed with theabove-described hole transporting material by any known method, forexample, a vacuum evaporation method, a spin coating method, a castingmethod, a printing method such as an ink jetting method, or LangmuirBlodgett (LB) method. The hole transporting layer may have anythickness, usually a thickness in the range of about 5 nm to 5 μm,preferably 5 to 200 nm. The hole transporting layer may have a singlelayer structure composed of one kind or two or more kinds of thematerials described above.

The p characteristics can be enhanced by doping the materials of holetransporting layer with any impurity. Examples are described in JapaneseUnexamined Patent Application Publication Nos. Hei 4-297076,2000-196140, and 2001-102175, and J. Appl. Phys., 95, 5773(2004).

A hole transporting layer with enhanced p characteristics is preferredbecause elements with low power consumption can be produced.

(Electron Transporting Layer)

The electron transporting layer includes a material which has a functionof transporting electrons. The electron transporting layer also includesan electron injecting layer and a hole blocking layer in a broad sense.The electron transporting layer may have a monolayer or multilayerstructure.

In an electron transporting layer having a monolayer structure and anelectron transporting layer having a multilayer structure, the electrontransporting material (also functioning as hole blocking material)constituting a layer adjacent to the light emitting layer is requiredonly to have a function of transporting electrons injected from thecathode to the light emitting layer. Such materials can be selected fromany conventionally known materials and can be used. Examples of suchmaterials include nitro-substituted fluorene derivatives,diphenylquinone derivatives, thiopyrane dioxide derivatives,carbodiimides, fluorenylidene methane derivatives, anthraquinodimethane,anthrone derivatives, and oxadiazole derivatives. In addition,thiadiazole derivatives in which the oxygen atom in the oxadiazole ringis replaced with a sulfur atom in the above oxadiazole derivatives, andquinoxaline derivatives having quinoxaline rings, which are known aselectron attractive groups, may also be used as materials for theelectron transporting layer. High molecular weight materials havingthese materials introduced in the macromolecular chain or having thesematerials as main chains may also be used.

Furthermore, materials for the electron transporting layer may be metalcomplexes of 8-quinolinol derivatives such as tris(8-quinolinol)aluminum(abbreviation: Alq₃), tris(5,7-dichloro-8-quinolinol)aluminum,tris(5,7-dibromo-8-quinolinol)aluminum,tris(2-methyl-8-quinolinol)aluminum, tris(5-metal-8-quinolinol)aluminum,and bis(8-quinolinol)zinc (abbreviation: Znq); and metal complexes ofwhich the central metals are replaced with In, Mg, Cu, Ca, Sn, Ga, orPb.

A thin film of the electron transporting layer can be formed with theelectron transporting material by any known method, for example, avacuum evaporation method, a spin coating method, a casting method, aprinting method such as an ink jetting method, or Langmuir Blodgett (LB)method. The electron transporting layer may have any thickness, usuallya thickness in the range of about 5 nm to 5 μm, preferably 5 to 200 nm.The electron transporting layer may have a single layer structurecomposed of one kind or two or more kinds of the materials describedabove.

(Blocking Layer)

The blocking layers include hole blocking layers and electron blockinglayers. These layers may be provided as needed in addition to theindividual layers constituting the carrier transporting functional layerunit 3 described above. Examples of the blocking layer are disclosed inJapanese Unexamined Patent Application Publication Nos. Hei 11-204258and Hei 11-204359, and hole blocking layers described in “Yuuki EL Soshito sono Kogyoka Saizensen (Front Line in Industrialization of Organic ELelement)”, p. 237, (Nov. 30, 1998 by N. T. S. Company).

The hole blocking layer also functions as an electron transporting layerin a broad sense. The hole blocking layer is composed of a hole blockingmaterial which has a function of transporting electrons but can barelytransport holes. Since the hole blocking layer transports electronswhile blocking holes, the layer will enhance the opportunity ofrecombination of electrons and holes. The structure of the electrontransporting layer may be used as a hole blocking layer as needed.Preferably, the hole blocking layer is arranged adjacent to the lightemitting layer.

The electron blocking layer also functions as a hole transporting layerin a broad sense. The electron blocking layer is composed of a materialwhich has a function of transporting holes but can barely transportelectrons. Since the electron blocking layer transports holes whileblocking electrons, the layer will enhance the opportunity ofrecombination of electrons and holes. The structure of the holetransporting layer may be used as an electron blocking layer. The holeblocking layer applied in the present invention preferably has athickness in the range of 3 to 100 nm, more preferably in the range of 5to 30 nm.

[Second Electrode: Cathode]

The cathode according to the present invention is an electrode which hasa light transmittance and a function of supplying holes to the carriertransporting functional layer group and the light emitting layer. Thecathode includes a metal, alloy, organic or inorganic conductivecompound, or a mixture thereof. Specific examples include gold,aluminum, silver, magnesium, lithium, magnesium/copper mixtures,magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indiummixtures, indium, lithium/aluminum mixtures, rare earth metals, andoxide semiconductors such as ITO, ZnO, TiO₂, and SnO₂.

The cathode can be prepared by forming a thin film of these conductivematerials by evaporation or sputtering. The cathode as a secondelectrode has a sheet resistance of preferably several hundred Ω/sq. orless, and the thickness selected in the range of generally 5 nm to 5 μm,preferably in the range of 5 to 200 nm.

[Other Components] <Gas Barrier Layer>

At the entire surface of one side or both sides of the transparentsubstrate (1), at least the side where the anode (first electrode) isformed, a gas barrier layer (2) having light transmittance is formed sothat permeation of components such as water and oxygen, whichdeteriorate the constituting materials of the organic EL element, can besuppressed.

The gas barrier layer (2) may be not only a coating film of an inorganicmaterial, but a coating film composed of a composite material includingan organic material or a hybrid coating material obtained by laminatingsuch coating films. The gas barrier layer (2) is preferably aninsulating film having light transmittance and a gas barrier property asfollows: water vapor permeability of about 0.01 g/m²·24 h or less(environmental condition: 25±0.5° C., relative humidity (90±2)%) basedon JIS (Japan Industrial Standards)-K7129 (2008); oxygen permeability ofabout 0.01 ml/m²·24 h·atm or less based on JIS-K7126 (2006); resistivityof 1×10¹² Ω·cm or more; and light transmission rate in the range ofvisible light of 80% or more.

Any materials can be used as the material for forming the gas barrierlayer (2), as long as the material can suppress permeation of, forexample, water and gas such as oxygen into the organic El element, whichdeteriorates the organic EL element.

The gas barrier layer (2) may include a coating film composed of aninorganic material such as silicon oxide, silicon nitride, siliconoxynitride, silicon carbide, silicon oxycarbide, aluminium oxide,aluminium nitride, titanium oxide, zirconium oxide, niobium oxide, andmolybdenum oxide, for example. Preferably, silicon compounds such assilicon nitride and silicon oxide is used as a main raw material.

The formation method of the gas barrier layer can be appropriatelyselected from conventionally known methods of producing films, such as avacuum evaporation method, a sputtering method, a magnetron sputteringmethod, a molecular beam epitaxy method, a cluster ion beam method, anion plating method, a plasma polymerization method, anatmospheric-pressure plasma polymerization method (see Japanese PatentApplication Laid Open Publication No. 2004-68143), a plasma CVD(Chemical Vapor Deposition) method, a laser CVD method, thermal CVDmethod, ALD (Atomic Layer Deposition) method, and a wet applicationmethod using polysilazane and the like.

<Sealing Material>

The exemplary organic EL panel (P) in FIG. 2 shows an organic EL panel(P) provided with an organic EL element (OLED) formed up to the cathode(7), further provided with a sealing member formed above.

As shown in FIG. 2, the entire surface of the organic EL element (OLED)is provided with a sealing adhesive (8) and sealed with the sealingsubstrate (10) having the gas barrier layer (9) on the outermostsurface.

The sealing member may have a concave shape or a flat shape, as long asthe sealing member is arranged so that the display region of the organicEL element is covered. The transparency and the electrical insulatingproperty are not particularly limited.

Specific examples include a glass substrate, a resin substrate, resinfilm, metal film (metal foil), and the like having flexibility. Examplesof the glass substrate include, in particular, soda lime glass, bariumand strontium containing glass, lead glass, aluminosilicate glass,borosilicate glass, barium borosilicate glass, quartz, and the like.Examples of the resin substrate include polycarbonate, acrylic,poly(ethylene terephthalate), polyether sulfide, polysulfone, and thelike.

Examples of the sealing adhesive include polyurethane adhesives,polyester adhesives, epoxy adhesives, and acrylic adhesives. A curingagent may be optionally used in combination as needed. A dry laminationmethod is preferred, but a hot-melt lamination method, an extrusionlamination method, or a co-extrusion lamination method may also be used.

Resin substrate and glass substrate can be preferably used as thesealing material according to the present invention because the organicEL element can be thinned. Preferably, the resin substrate has watervapor permeability of 1×10⁻³ g/m²·24 h or less which is measured inaccordance with JIS K 7129-1992 at the temperature of 25±0.5° C. andrelative humidity of 90±2% RH. More preferably, the resin substrate hasoxygen permeability of 1×10⁻³ ml/m²·24 h·atm (1 atm corresponds to1.01325×10⁵ Pa) which is measured in accordance with JIS K 7126-1987,and water vapor permeability of 1×10⁻³ g/m²·24 h or less at thetemperature of 25±0.5° C. and relative humidity of 90±2% RH. In order tosatisfy the conditions, a gas barrier layer is preferably provided,which is equivalent to the one explained for the base material describedabove.

At the gap between the sealing member and the display region (lightemitting region) of the organic EL element can be injected inactive gassuch as nitrogen gas and argon gas, or an inactive liquid such assilicon oil, for the purpose of forming a gaseous or a liquid phase. Thegap between the sealing member and the display region of the organic ELelement may be vacuum. Alternatively, the gap may be filled with ahygroscopic compound.

The sealing film may be provided on the substrate having lighttransmittance, while completely covering the organic functional layerunit of the organic EL element and exposing the terminals of the anode(3) as the first electrode and the cathode (7) as the second electrodeof the organic EL element.

<<Specific Structure of the Organic EL Panel>>

Subsequently, the specific structure of the organic EL panel accordingto the present invention is described.

The organic EL panel according to the present invention includes a lightemitting portion region which is shaped by the organicelectroluminescence element and a light-transmitting non-light emittingportion region.

Hereinafter, the specific structure of the organic EL panel includingthe light emitting portion region (light emitting area) and non-lightemitting portion is explained.

Embodiment 1: Formation Method 1 of Organic EL Panel

FIG. 3 is a schematic cross-sectional view showing an exemplarystructure of the organic EL panel (P) according to the invention havingan organic EL element (Embodiment 1).

The organic EL panel (P) illustrated in FIG. 3 has independent lightemission areas shaped by arranging organic EL panels separate from eachother on a transparent base material (1) having light transmittance inthe organic EL element described in reference to FIG. 2 above. For moredetails, on the transparent base material (1) having the gas barrierlayer (2) are arranged a plurality of organic EL elements (OLEDs)constituted by, for example, the anodes (3), the organic functionallayer units (U), the cathodes (7), and so forth.

According to the structure illustrated in FIG. 3, the light emittingareas are regions in which all of the anode (3), the organic functionallayer unit (U), and the cathode (7) exist. A region between the lightemitting areas is the light-transmitting non-light emitting area (12).In the structure illustrated in FIG. 3, a finger at the lower surfaceside is irradiated with light (L1) from the finger surface side havingthe anodes (3). The image sensor (S) is arranged at the upper surfaceside of the light-transmitting non-light emitting portion (12).

In the structure illustrated in FIG. 3, most preferably, the anodes (3)are constituted by light-transmitting electrodes and the cathodes (7)are constituted by non-light emitting electrodes, however, both of theanodes (3) and the cathodes (7) may be constituted by light-transmittingtransparent electrodes.

Embodiment 2: Formation Method 2 of Organic EL Panel

The organic EL panel (P) having a structure illustrated in FIG. 4 showsanother exemplary structure in which the cathodes (7) are constituted bynon-light transmitting electrodes, in particular, in the structureexplained above in reference to FIG. 3. Such structure preventsirradiation of the image sensor side with irregular light which affectsthe measurement accuracy of the image sensor from the cathode (7) sideof the organic EL element. Accordingly, the image sensor (S) can bearranged on the entire surface including the light emitting area.

Embodiment 3: Formation Method 3 of Organic EL Panel

The organic EL panel (P) having the structure illustrated in FIG. 5shows a method of forming the organic EL element in which thelight-transmitting anode (3) is formed at the entire surface of thelight emitting area and the non-light emitting portion (12), so thatonly the organic functional layer units (U) and the cathodes (7) shapethe light emitting area.

The light emitting area is required to have a structure in which all ofthe anode (3), the organic functional layer units (U), and the cathodes(7) are present in a single plane. As illustrated in FIG. 5, the regionin which only the anode (3) is present functions as the non-lightemitting portion (12).

Embodiment 4: Formation Method 4 of Organic EL Panel

The organic EL panel (P) having the structure illustrated in FIG. 6shows a method of forming the organic EL element in which the anode (3)and the organic functional layer unit (U) are formed at the entiresurface of the light emitting area and the non-light emitting portion(12), so that only the cathodes (7) shape the light emitting area.

The light emitting area is required to have a structure in which all ofthe anode (3), the organic functional layer unit (U), and the cathodes(7) are present in a single plane. As illustrated in FIG. 6, the regionin which the cathodes (7) are not present functions as the non-lightemitting portion (12).

Embodiment 5: Formation Method 5 of Organic EL Panel

The organic EL panel (P) having the structure illustrated in FIG. 7shows a method of forming the organic EL element in which the anodes (3)and the organic functional layer unites (U) are formed only at the lightemitting area as illustrated in FIG. 4. The cathode (7) preferably haslight transmittance since the cathode (7) is also present at thenon-light emitting portion (12).

The light emitting area is required to have a structure that all of theanodes (3), the organic functional layer units (U), and the cathode (7)are present in a single plane. As shown in FIG. 7, the region in whichthe anodes (3) and the organic functional layer units (U) are notpresent functions as the non-light emitting portion (12).

Embodiment 6: Formation Method 6 of Organic EL Panel

The formation method of the organic EL panel (P) illustrated in FIG. 8can be a method of forming the non-light emitting portion (U2) in theorganic functional layer unit by forming the anode (3), organicfunctional layer unit (U), and the cathode (7) on the entire surface ofthe transparent substrate (1+2), followed by irradiating the region forforming the non-light emitting portion (12) with ultraviolet rays (UV)by an ultraviolet-ray irradiating apparatus (13) through a mask member(M) so that the light emitting function of the organic functional layerunit is deactivated.

The method is not particularly limited, and may be either a method oflight irradiation after forming the organic functional layer unit (U) ora method of patterning the light emitting area by irradiating theorganic EL panel (P) with light after sealing process. The latter methodis preferred because the organic EL panel after sealing can be subjectedto light irradiation during exposure to an air atmosphere, whichrealizes an easy light irradiation step and low manufacturing costs.

As the first step, as illustrated in FIG. 8A, the organic EL element isformed by the sealing process after forming an anode (3), organicfunctional layer unit (U), and the cathode (7) on the entire surface ofthe transparent substrate (1).

Subsequently, irradiation with ultraviolet rays (UV) by theultraviolet-ray irradiating apparatus (13) is performed after shieldingthe region except for the region of the non-light emitting portion (12)with the mask member (M)

By the irradiation process with the ultraviolet rays described above, asillustrated in FIG. 8B showing the second step, the function of theorganic functional layer unit (U1) is deactivated in the regionirradiated with the ultraviolet rays (UV) so that the non-light emittingportion (U2) is shaped.

Subsequently, as illustrated in FIG. 8C showing the third step, theimage sensor (S) is arranged above the non-light emitting portion (12,U2) to manufacture the fingerprint information reader (100).

In the formation method of the Embodiment 6, both of the anode (3) andthe cathode (7) are required to be formed by a transparent electrodebecause the anode (3) and the cathode (7) are present in the area of thenon-light emitting portion (12).

In the first step illustrated in FIG. 8A, which is the light irradiationstep for pattern forming, the light for irradiation includes at leastultraviolet rays (UV) and may further include visible light or infraredrays. The ultraviolet rays according to the present invention refer toelectromagnetic waves having a wavelength longer than the wavelength ofX rays and shorter than the minimum wavelength of visible rays,specifically, within the wavelength range within 1 to 400 nm.Preferably, the applied light for irradiation has local maximumwavelengths at 355 nm, 365 nm, 380 nm, 405 nm, and so forth.

The generation means and the irradiation means of the light forirradiation are not particularly limited, as long as a predeterminedregion can be irradiated with light which is generated by aconventionally known irradiation device.

The a light source for illumination which can be used in the presentinvention include a high-pressure mercury lamp, a low-pressure mercurylamp, a hydrogen (deuterium) lamp, a rare gas (such as xenon, argon,helium, and neon) discharge lamp, nitrogen laser, excimer laser (such asXeCl, XeF, KrF, and KrCl), hydrogen laser, halogen laser, harmonic wavesof a visible (LD) laser to an infrared laser (THG (Third HarmonicGeneration) light of YAG laser), and the like.

The method of laser light irradiation includes moving the laser lightsource and the organic functional layer unit (U) relative to each otherwhile irradiating the organic functional layer unit (U) with the laserlight in spot, so that the patterned region can be irradiated with lightby scanning the laser light irradiation position.

<<Embodiment of Optical Fingerprint Authentication Device Provided withFingerprint Information Reader>>

Next, with reference to the drawings will now be described specificstructures of the fingerprint information reader constituting theoptical fingerprint authentication device using the organic EL panelprovided with the organic EL element according to the present invention.

Embodiment 7: Exemplary Configuration 1 of Fingerprint InformationReader

FIG. 9 is a schematic diagram showing an exemplary fingerprintinformation reader having an organic EL panel provided with adoughnut-shaped organic EL element (Embodiment 7).

The cross-sectional view illustrated in FIG. 9 shows a same structure asthe fingerprint information reader (100) constituting the opticalfingerprint authentication device previously described in reference toFIG. 1. There are provided an organic EL panel (P) which is constitutedby the organic EL element (OLED) and a light-transmitting non-lightemitting portion (12), and by the image sensor (S) which is arrangedbelow the light-transmitting non-light emitting portion (12) andoptically reads fingerprint information of a specimen. 11 is a glasssubstrate to hold the finger.

The fingerprint pattern information is obtained by irradiation of thefingerprint surface of the finger (F) with the irradiation light (L1)from the organic EL element (OLED) and receiving reflection light (L2),which is a light signal, by the image sensor (S).

The shape of the organic EL element (OLED) of the fingerprintinformation reader (100) having such structure may be, as illustrated inB of FIG. 9, a doughnut-shaped continuous organic EL element (OLED)arranged at the peripheral portion of the elliptic organic EL panel (P).The gap portion at the center is formed as the non-light emittingportion (12). Such embodiment of the organic EL element enables tomeasure the fingerprint pattern from a wide aperture.

C of FIG. 9 is a bottom view of the structure illustrated in A of FIG. 9and shows the finger (F), which is the specimen, the doughnut-shapedorganic EL element (OLED), and the image sensor (S) arranged at thenon-light emitting region thereof. In C of FIG. 9, the glass substrate(11) is omitted.

Embodiment 8: Exemplary Configuration 2 of Optical FingerprintAuthentication Device

FIG. 10 is a schematic diagram showing an exemplary optical fingerprintauthentication device having an organic EL panel provided with arectangular-shaped organic EL element (Embodiment 8).

The schematic cross-sectional view illustrated in A of FIG. 10 issimilar to that of the structure illustrated in A of FIG. 9 as describedabove, however, the organic EL panel (P) and the image sensor (S) ischaracterized by their rectangular shapes as illustrated in B and C ofFIG. 10. The optical fingerprint authentication device having suchstructure, has difficulty in covering the entire fingerprint, which hada round shape, but provides an effective method for pattern detection ofan important center portion of the fingerprint.

As illustrated in B of FIG. 10, the organic EL panel (P) has arectangular shape having a continuous organic EL element (OLED) isarranged at the edges and the non-light emitting portion (12) alsohaving a rectangular area formed inside, so that the image sensor (S)has a rectangular form corresponding to the form of the non-lightemitting portion (12) as illustrated in C of FIG. 10. In C of FIG. 10,the glass substrate (11) is omitted.

On the organic EL panel (P) as illustrated in FIG. 9 and FIG. 10, theorganic EL element (OLED) having a specific shape, such as adoughnut-shape or rectangular shape, can be formed by forming the anode(3), the organic functional layer unit (U), and the cathode (7) using amask member of a desired shape by, for example, a vacuum evaporationmethod (such as a resistance heating deposition method, an electron beamdeposition method, an ion plating method, and an ion beam evaporationmethod), a sputtering method, a reactive sputtering method, a molecularbeam epitaxy method, a plasma polymerization method, anatmospheric-pressure plasma polymerization method, a plasma CVD method,a laser CVD method, a thermal CVD method, and wet application methodssuch as a screen printing method. Alternatively, as illustrated in FIG.8, the function of the organic functional layer unit can be deactivatedto form the organic EL element having a desired shape.

Embodiment 9: Exemplary Configuration 3 of Optical FingerprintAuthentication Device

FIG. 11 is a schematic diagram showing an example of an opticalfingerprint authentication device having an organic EL panel withstrip-shaped organic EL elements arranged separately at four sides(Embodiment 9).

The organic EL panel (P) according to the Embodiment 9 is constitutedby, as illustrated in B of FIG. 11, independent and strip-shaped organicEL elements (OLEDs) arranged at each of the four sides of therectangular organic EL panel (P). The non-light emitting portion (12)and the image sensor (S) have a rectangular shape. In C of FIG. 11, theglass substrate (11) is omitted.

Embodiment 10: Exemplary Configuration 4 of Optical FingerprintAuthentication Device

FIG. 12 is a schematic diagram showing an exemplary optical fingerprintauthentication device having a round-shaped organic EL panel having arectangular-shaped non-light emitting portion at the center (Embodiment10).

As illustrated in B of FIG. 12, the peripheral portion of the organic ELpanel (P) of the Embodiment 10 has a elliptic shape as in FIG. 9, andthe non-light emitting portion (12) and the image sensor (S) arranged atthe center portion have a rectangular shape. In C of FIG. 12, the glasssubstrate (11) is omitted.

Embodiment 11: Exemplary Configuration 5 of Optical FingerprintAuthentication Device

FIG. 13 is a schematic diagram showing an exemplary optical fingerprintauthentication device having an organic EL panel having a plurality oforganic EL elements arranged in a stripe shape in parallel (Embodiment11).

According to the structure illustrated in B and C of FIG. 13, aplurality of organic EL elements (OLEDs) having different sizes arearranged in a stripe shape in parallel on the organic EL panel (P) of aelliptic shape. In C of FIG. 13, the glass substrate (11) is omitted.

In such a structure, the non-light emitting portion (12) is between theindividual organic EL elements (OLEDs).

According to the structure illustrated in FIG. 13, the detectable areais narrow when the organic EL elements (OLEDs) occupy too large area.Therefore, the aperture rate (%) which is defined as the ratio of thearea of the non-light emitting portion (12) to the entire area of theorganic EL element (P) is preferably 50% or more, more preferably 60% ormore, particularly preferably 70% or more. Because the total amount oflight emission from the organic EL element (OLED) is reduced dependingon the increase of the aperture rate, the organic EL element (OLED)having high emission intensity is preferably used. Examples of theorganic EL element (OLED) having high emission intensity includes, forexample, a tandem type organic EL element having two or more organicfunctional layer units including a light emitting layer via anintermediate layer or an intermediate electrode.

Embodiment 12: Exemplary Configuration 6 of Optical FingerprintAuthentication Device

FIG. 14 is a schematic diagram showing an exemplary optical fingerprintauthentication device having an organic EL panel with a plurality oforganic EL elements arranged separately at the peripheral portion(Embodiment 12).

As illustrated in B of FIG. 14, a plurality of rectangular organic ELelements (OLEDs) are arranged independently at the peripheral portion ofthe elliptic organic EL panel (P), and the non-light emitting portion(12) is formed between the organic EL elements (OLEDs) and at the centerportion. In C of FIG. 14, the glass substrate (11) is omitted.

Such a structure is preferred in that a high aperture rate can beobtained in comparison with the structure of a stripe shape exemplifiedin FIG. 13.

<<Fingerprint Authentication Method>>

The specific fingerprint authentication method using the opticalfingerprint authentication device according to the present invention canbe appropriately selected for use from the methods described in, forexample, Japanese Patent Application Laid Open Publication Nos.2003-256377, 2004-005619, 2004-246586, 2005-063246, 2005-118289,2006-244224, 2007-289457, 2007-328511, 2008-009821, 2008-171238,2009-271825, 2011-141880, and the like.

Although embodiments of the present invention have been described andillustrated in detail, the disclosed embodiments are made for purposesof illustration and example only and not limitation. The scope of thepresent invention should be interpreted by terms of the appended claims.

INDUSTRIAL APPLICABILITY

The optical fingerprint authentication device according to the presentinvention has a thin structure, includes a various shapes of lightsource for illumination according to purposes, and can be preferablyused for personal authentication using fingerprint patterns in ATM in abank, a cellular phone, a personal data assistant, a personal computer,and the like.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 transparent base material    -   2, 9 gas barrier layer    -   3 anode    -   3RM raw material for forming anode    -   4 carrier transporting functional layer group 1    -   5 light emitting layer    -   6 carrier transporting functional layer group 2    -   7 cathode    -   8 sealing adhesive layer    -   10 sealing substrate    -   11 glass substrate    -   12 light-transmitting region, non-light emitting portion    -   13 ultraviolet-ray irradiating apparatus    -   100 fingerprint information reader    -   F finger    -   L1 light, irradiation light    -   L2 reflection light, light signal    -   M mask    -   OLED organic EL element    -   P organic EL panel    -   S image sensor    -   U organic functional layer unit    -   U2 non-light emitting portion (organic functional layer unit)    -   UV ultraviolet rays

1. An optical fingerprint authentication device which comprises at leasta light source and an image sensor and detects diffused light, whereinthe light source is an organic electroluminescence panel, wherein theorganic electroluminescence panel comprises a light emitting portionregion and a light-transmitting non-light emitting portion, the lightemitting portion region being shaped by an organic electroluminescenceelement, and wherein a fingerprint information reader having the imagesensor arranged at a position adjacent to the non-light emitting portionis provided.
 2. The optical fingerprint authentication device accordingto claim 1, wherein the organic electroluminescence element comprises anorganic functional layer unit between a pair of electrodes facing eachother, one of the electrodes being a light-transmitting electrode, andanother of the electrodes being a non-light-transmitting electrode. 3.The optical fingerprint authentication device according to claim 1,wherein the organic electroluminescence element comprises an organicfunctional layer unit between a pair of electrodes facing each other,each of the electrodes being a light-transmitting electrode.
 4. Theoptical fingerprint authentication device according to claim 2, whereinthe light-transmitting electrode comprises an oxide semiconductor or athin film of a metal or an alloy.
 5. The optical fingerprintauthentication device according to claim 2, wherein thelight-transmitting non-light emitting portion comprises alight-transmitting electrode.
 6. The optical fingerprint authenticationdevice according to claim 2, wherein the light-transmitting non-lightemitting portion comprises the light-transmitting electrode and theorganic functional layer unit.
 7. The optical fingerprint authenticationdevice according to claim 1, wherein the organic electroluminescencepanel comprises: an organic electroluminescence element having acontinuous structure arranged at a peripheral portion; and thelight-transmitting non-light emitting portion at a center portion. 8.The optical fingerprint authentication device according to claim 1,wherein the organic electroluminescence panel comprises a plurality oforganic electroluminescent elements which are arranged in parallel in astripe shape, and wherein the light-transmitting non-light emittingportion is formed between the organic electroluminescent elements whichare in a stripe shape.
 9. The optical fingerprint authentication deviceaccording to claim 1, wherein the organic electroluminescence panelcomprises: a plurality of independent organic electroluminescentelements arranged separately at a peripheral portion, and thelight-transmitting non-light emitting portion at a center portion. 10.The optical fingerprint authentication device according to claim 1,wherein the organic electroluminescence panel emits light which has awavelength in a visible light region.
 11. The optical fingerprintauthentication device according to claim 1, wherein the organicelectroluminescence panel emits light which has a wavelength in aninfrared region.